Surfaced when running sunfishcode/misc-tests. When trying to
truncate the file without the __WASI_RIGHT_PATH_FILESTAT_SET_SIZE
right, error __WASI_ENOTCAPABLE was correctly returned, however,
the guest fd pointer was not encoded to -1 in that case. This
commit fixes it by taking out the guest fd encoding out of the
conditional branch which turns out obsolete.
This adds the C WASI implementation as a new crate, wasmtime-wasi-c,
and adds a command-line flag to the wasmtime command-line driver to
select which WASI implementation to use.
Fix the following warning from Rust 1.35:
warning: cannot borrow `*self` as mutable because it is also borrowed as immutable
--> wasmtime-runtime/src/instance.rs:473:25
|
465 | } else if let Some(start_export) = self.module.exports.get("_start") {
| ----------- immutable borrow occurs here
...
473 | self.invoke_function(*func_index)
| ^^^^ ----------- immutable borrow later used here
| |
| mutable borrow occurs here
|
= note: #[warn(mutable_borrow_reservation_conflict)] on by default
= warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
= note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
I thought it might be useful for future WASI users to have the WASI tutorial written not only in C but also in Rust.
I'm also happy to keep the tutorial up to date with the current state of WASI target in Rust.
In more detail, this commit:
* makes fd_prestat_get safe
* rewrites fd_prestats_get_entry in (safe) Rust
* creates helper macros for rwlock read lock and unlock
If a path_open call is requesting __WASI_RIGHT_FD_FILESTAT_SET_SIZE,
interpret that as a request for write privleges. If it is requesting
O_TRUNC, require __WASI_RIGHT_PATH_FILESTAT_SET_SIZE, since this is
a path operation rather than a FD operation.
Document that `setjmp`/`longjmp` and C++ exceptions are unsupported, and
update the documentation about the function signature mismatch bug to
reflect that it's now just a warning rather than a fatal error.
